/*
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.l2j.gameserver.taskmanager;

import static net.sf.l2j.gameserver.taskmanager.TaskTypes.TYPE_NONE;
import static net.sf.l2j.gameserver.taskmanager.TaskTypes.TYPE_SHEDULED;
import static net.sf.l2j.gameserver.taskmanager.TaskTypes.TYPE_TIME;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.ScheduledFuture;
import java.util.logging.Level;
import java.util.logging.Logger;

import javolution.util.FastList;
import javolution.util.FastMap;

import net.sf.l2j.L2DatabaseFactory;
import net.sf.l2j.gameserver.ThreadPoolManager;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskCleanUp;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskJython;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskOlympiadSave;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskRaidPointsReset;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskRecom;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskScript;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskRestart;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskSevenSignsUpdate;
import net.sf.l2j.gameserver.taskmanager.tasks.TaskShutdown;

/**
 * @author Layane
 */
public final class TaskManager
{
    protected static final Logger _log = Logger.getLogger(TaskManager.class.getName());

    protected static final String[] SQL_STATEMENTS =
    {
    	"SELECT id,task,type,last_activation,param1,param2,param3 FROM global_tasks",
    	"UPDATE global_tasks SET last_activation=? WHERE id=?",
    	"SELECT id FROM global_tasks WHERE task=?",
		"INSERT INTO global_tasks (task,type,last_activation,param1,param2,param3) VALUES(?,?,?,?,?,?)"
    };

    private final FastMap<Integer, Task> _tasks = new FastMap<Integer, Task>();
    protected final FastList<ExecutedTask> _currentTasks = new FastList<ExecutedTask>();

    public class ExecutedTask implements Runnable
    {
        int id;
        long lastActivation;
        Task task;
        TaskTypes type;
        String[] params;
        ScheduledFuture<?> scheduled;

        public ExecutedTask(Task ptask, TaskTypes ptype, ResultSet rset) throws SQLException
        {
            task = ptask;
            type = ptype;
            id = rset.getInt("id");
            lastActivation = rset.getLong("last_activation");
            params = new String[] { rset.getString("param1"), rset.getString("param2"), rset.getString("param3") };
        }

        public void run()
        {
            task.onTimeElapsed(this);
            lastActivation = System.currentTimeMillis();

            Connection con = null;

            try
            {
                con = L2DatabaseFactory.getInstance().getConnection();
                PreparedStatement statement = con.prepareStatement(SQL_STATEMENTS[1]);
                statement.setLong(1, lastActivation);
                statement.setInt(2, id);
                statement.executeUpdate();
                statement.close();
            }
            catch (SQLException e)
            {
            	_log.log(Level.WARNING, "Cannot updated the Global Task " + id + ": " + e.getMessage(), e);
            }
            finally
            {
                try { con.close(); } catch (Exception e) {}
            }

            if (type == TYPE_SHEDULED || type == TYPE_TIME)
                stopTask();
        }

        @Override
		public boolean equals(Object object)
        {
            return id == ((ExecutedTask) object).id;
        }

        public Task getTask()
        {
            return task;
        }

        public TaskTypes getType()
        {
            return type;
        }

        public int getId()
        {
            return id;
        }

        public String[] getParams()
        {
            return params;
        }

        public long getLastActivation()
        {
            return lastActivation;
        }

        public void stopTask()
        {
            task.onDestroy();

            if (scheduled != null)
            	scheduled.cancel(true);

            _currentTasks.remove(this);
        }

    }

	public static TaskManager getInstance()
	{
		return SingletonHolder._instance;
	}

    private TaskManager()
    {
        initializate();
        startAllTasks();
    }

    private void initializate()
    {
        registerTask(new TaskCleanUp());
        registerTask(new TaskScript());
        registerTask(new TaskJython());
        registerTask(new TaskOlympiadSave());
        registerTask(new TaskRaidPointsReset());
        registerTask(new TaskRecom());
        registerTask(new TaskRestart());
        registerTask(new TaskSevenSignsUpdate());
        registerTask(new TaskShutdown());
    }

    public void registerTask(Task task)
    {
        int key = task.getName().hashCode();
        if (!_tasks.containsKey(key))
        {
            _tasks.put(key, task);
            task.initializate();
        }
    }

    private void startAllTasks()
    {
        Connection con = null;
        try
        {
        	con = L2DatabaseFactory.getInstance().getConnection();
        	PreparedStatement statement = con.prepareStatement(SQL_STATEMENTS[0]);
        	ResultSet rset = statement.executeQuery();

        	while (rset.next())
        	{
        		Task task = _tasks.get(rset.getString("task").trim().toLowerCase().hashCode());
        		if (task == null)
        			continue;

        		TaskTypes type = TaskTypes.valueOf(rset.getString("type"));
        		if (type != TYPE_NONE)
        		{
        			ExecutedTask current = new ExecutedTask(task, type, rset);
        			if (launchTask(current))
        				_currentTasks.add(current);
        		}
        	}
            rset.close();
            statement.close();
        }
        catch (Exception e)
        {
        	_log.log(Level.SEVERE, "Error while loading Global Task table: " + e.getMessage(), e);
        }
        finally
        {
            try { con.close(); } catch (Exception e) {}
        }
    }

    private boolean launchTask(ExecutedTask task)
    {
        final ThreadPoolManager scheduler = ThreadPoolManager.getInstance();
        final TaskTypes type = task.getType();
		long delay, interval;
		
		switch(type)
		{
			case TYPE_STARTUP:
				task.run();
				return false;
			case TYPE_SHEDULED:
				delay = Long.valueOf(task.getParams()[0]);
				task.scheduled = scheduler.scheduleGeneral(task, delay);
				return true;
			case TYPE_FIXED_SHEDULED:
				delay = Long.valueOf(task.getParams()[0]);
				interval = Long.valueOf(task.getParams()[1]);
				task.scheduled = scheduler.scheduleGeneralAtFixedRate(task, delay, interval);
				return true;
			case TYPE_TIME:
				try
				{
					Date desired = DateFormat.getInstance().parse(task.getParams()[0]);
					long diff = desired.getTime() - System.currentTimeMillis();
					if (diff >= 0)
					{
						task.scheduled = scheduler.scheduleGeneral(task, diff);
						return true;
					}
					_log.info("Task " + task.getId() + " is obsoleted.");
				}
				catch (Exception e) {}
				break;
			case TYPE_SPECIAL:
				ScheduledFuture<?> result = task.getTask().launchSpecial(task);
				if (result != null)
				{
					task.scheduled = result;
					return true;
				}
				break;
			case TYPE_GLOBAL_TASK:
				interval = Long.valueOf(task.getParams()[0]) * 86400000L;
				String[] hour = task.getParams()[1].split(":");
				
				if (hour.length != 3)
				{
					_log.warning("Task " + task.getId() + " has incorrect parameters");
					return false;
				}
				
				Calendar check = Calendar.getInstance();
				check.setTimeInMillis(task.getLastActivation() + interval);
				
				Calendar min = Calendar.getInstance();
				try
				{
					min.set(Calendar.HOUR_OF_DAY, Integer.parseInt(hour[0]));
					min.set(Calendar.MINUTE, Integer.parseInt(hour[1]));
					min.set(Calendar.SECOND, Integer.parseInt(hour[2]));
				}
				catch (Exception e)
				{
					_log.log(Level.WARNING, "Bad parameter on task " + task.getId() + ": " + e.getMessage(), e);
					return false;
				}
				
				delay = min.getTimeInMillis() - System.currentTimeMillis();
				
				if (check.after(min) || delay < 0)
					delay += interval;
				
				task.scheduled = scheduler.scheduleGeneralAtFixedRate(task, delay, interval);
				return true;
			default:
				return false;
		}
		return false;
    }

    public static boolean addUniqueTask(String task, TaskTypes type, String param1, String param2, String param3)
    {
        return addUniqueTask(task, type, param1, param2, param3, 0);
    }

    public static boolean addUniqueTask(String task, TaskTypes type, String param1, String param2, String param3, long lastActivation)
    {
        Connection con = null;

        try
        {
            con = L2DatabaseFactory.getInstance().getConnection();
            PreparedStatement statement = con.prepareStatement(SQL_STATEMENTS[2]);
            statement.setString(1, task);
            ResultSet rset = statement.executeQuery();

            if (!rset.next())
            {
                statement = con.prepareStatement(SQL_STATEMENTS[3]);
                statement.setString(1, task);
                statement.setString(2, type.toString());
                statement.setLong(3, lastActivation);
                statement.setString(4, param1);
                statement.setString(5, param2);
                statement.setString(6, param3);
                statement.execute();
            }

            rset.close();
            statement.close();

            return true;
        }
        catch (SQLException e)
        {
        	_log.log(Level.WARNING, "Cannot add the unique task: " + e.getMessage(), e);
        }
        finally
        {
            try { con.close(); } catch (Exception e) {}
        }

        return false;
    }

    public static boolean addTask(String task, TaskTypes type, String param1, String param2, String param3)
    {
        return addTask(task, type, param1, param2, param3, 0);
    }

    public static boolean addTask(String task, TaskTypes type, String param1, String param2, String param3, long lastActivation)
    {
        Connection con = null;

        try
        {
            con = L2DatabaseFactory.getInstance().getConnection();
            PreparedStatement statement = con.prepareStatement(SQL_STATEMENTS[3]);
            statement.setString(1, task);
            statement.setString(2, type.toString());
            statement.setLong(3, lastActivation);
            statement.setString(4, param1);
            statement.setString(5, param2);
            statement.setString(6, param3);
            statement.execute();

            statement.close();
            return true;
        }
        catch (SQLException e)
        {
        	_log.log(Level.WARNING, "Cannot add the task:  " + e.getMessage(), e);
        }
        finally
        {
            try { con.close(); } catch (Exception e) {}
        }

        return false;
    }
    
	@SuppressWarnings("synthetic-access")
	private static class SingletonHolder
	{
		protected static final TaskManager _instance = new TaskManager();
	}
}